Adsorption Capacity of Ca2+ by Hydrochloric Acid Activated Kaolin

A high concentration of calcium ions in water is a problem as it can cause blockages in engine pipes. Adsorption is a relatively cheap and straightforward method that can be used to reduce the calcium ion content in water. Kaolin is a mineral that has a potential as an adsorbent and whose adsorption capacity can be increased by activation. This research studied the adsorption capacity of activated kaolin by hydrochloric acid against Ca2+ ions. Kaolin was chemically activated using 6 M HCl solution for 24 hours. The adsorption contact time in batches was varied with time variations of 30, 90, 150, and 180 minutes. The maximum adsorption capacity of activated kaolin to the Ca2+ was determined by varying the initial concentrations of water samples, namely 4, 7, 10, and 13 mg/L. The concentration of Ca2+ was determined by a titration method using ethylene diamine tetraacetate (EDTA). The results showed that the activation of kaolin with 6 M HCl at the optimum contact time of adsorption, namely 150 minutes, increased the percentage of adsorbed Ca ions to 2 times of that of natural kaolin, from 33.3% to 68.3%. Based on the Langmuir equation, the maximum adsorption capacity of calcium ions by activated kaolin HCl 6 M increased 1.7 times from natural kaolin to 0.346 mg/g.

Nickel recovery from precipitate of NCA lithium-ion battery leach liquor by using disodium ethylene diamine tetraacetate

The nickel cobalt aluminium oxides (NCA) type Li-ion battery is a type of battery currently used in electric vehicles. The UGM battery team has recycled this type of battery to obtain high purity lithium metal. Aside from lithium, the NCA battery contains high-value metals, nickel is one of them. This experiment aims to test the ease of nickel to chelate with disodium ethylene diamine tetraacetate (EDTA). The experiment was carried out by means of a triple neck flask for 4 hours. The samples were taken at certain minutes and then fitted using a pseudo homogeneous first-order reaction equation. The chelate formed was further processed through multilevel precipitation or electrodialysis to separate nickel. Based on the experiment, nickel formed chelates optimally at 60°C using 0.086 M EDTA with the reaction constant for nickel being 1.4819 min−1. The Arrhenius constant and activation energy for nickel were 3.48×1011min−1 and 76,907 J/mole, respectively.

Evaluation of Bio-Based Extraction Methods by Spectroscopic Methods

New technologies are in development regarding the preservation of waterlogged archaeological wood items contaminated with Fe/S species. To this purpose, a bio-based treatment to extract these harmful species before further damages occur is presented. Thiobacillus denitrificans and desferoxamine were employed based on their specific properties to solubilize iron sulfides and uptake iron. The biological treatment was compared with oxidizing and complexing agents (sodium persulfate and ethylene diamine tetraacetate) traditionally used in conservation-restoration. Mock-ups of fresh balsa as well as fresh and archeological oak and pinewood were prepared to simulate degraded waterlogged wood by immersion in corrosive Fe/S solutions. The efficiency of both biological and chemical extraction methods was evaluated through ATR-FTIR and Raman spectroscopies and validated by statistical approach. Results showed that treatments did not affect the wood composition, meaning that no wood degradation was induced. However, the chemical method tended to bleach the samples and after treatment, reduced sulfur species were still identified by Raman analyses. Finally, statistical approaches allowed validating ATR-FTIR results.

Impact of the nature of anticoagulant on the determination of gamma glutamyl transferase activity in blood

Introduction - La gamma-glutamyl transférase (GGT) est couramment utilisée comme marqueur très sensible des maladies hépatobiliaires, de la consommation d’alcool et plus récemment, comme biomarqueur prédictif d’événements cardiovasculaires. Dans la pratique actuelle, les laboratoires mesurent l’activité de la GGT sur un tube contenant de l’héparinate de lithium. Sauf qu’il n’y a aucune preuve que l’activité de la GGT puisse être déterminée de manière fiable avec cet anticoagulant. Le but de cette étude est d’évaluer l’impact de l’anticoagulant sur la détermination de l’activité de la GGT au niveau sanguin. Matériel et méthodes - Des échantillons sanguins de 30 patients ont été recueillis sur trois types de tubes: un tube sec, un tube contenant de l’héparinate de lithium et un autre contenant de l’éthylène diamine tétraacétate de dipotassium (K2-EDTA). L’analyse statistique comprend des études de corrélation, l’analyse de Bland Altman, ainsi que la comparaison des biais avec la limite de changement analytique (LCA) et la valeur de changement de référence (VCR). Résultats - Les résultats obtenus sur les plasmas héparinés sont globalement surestimés comparativement au sérum (p = 0.001). Tandis que les résultats obtenus sur les plasmas EDTA sont plus comparables à ceux du sérum (p = 0.356). En prenant le tube sec comme référence, le biais calculé pour les échantillons de plasmas héparinés (+ 49.55%) est plus élevé que la LCA (5.24%) et la VCR (37.52%). En ce qui concerne le K2-EDTA, ce biais (-13.40%) est inférieur à la VCR, mais supérieur à la LCA. Conclusion - Nos résultats montrent que la détermination de l’activité de la GGT doit être effectuée sur des échantillons sériques de préférence. Si jamais du plasma devait être utilisé, nous recommandons d’utiliser l’EDTA comme anticoagulant.